AD plant planned for US
However, Portland-based Columbia Biogas is planning to break the mould and construct an AD plant that will convert commercial food waste into methane gas for the production of electricity.
The plans will see the AD plant constructed on an 11-acre site. It will be designed to process 194,000 tonnes a year of solid and liquid food leftovers from both commercial and industrial sources. It will not, however, take food from residential sources, nor will it process yard waste.
‘We’re capturing the benefits of food waste that would otherwise be hauled long distances to a landfill,’ said the president of Columbia Biogas John McKinney. By-products of this AD plant include liquid fertiliser, water, heat and fibre soil additive.
Upon completion the biogas plant, which McKinney claims will be the first of its kind in the US, will generate 5kW a day of renewable electricity, benefitting around 5,000 households.
And while community groups and the city of Portland are backing the proposal, local residents lack enthusiasm over concerns about odour and traffic noise.
However, according to McKinney the plant will be completely enclosed with negative air pressure inside, resulting in air being pulled inside the facility any time a door is opened. In addition, the contaminated air will be scrubbed before being discharged from the facility. 60 trucks will arrive at the facility each day.